One of the best runners know that symmetry issues. Whenever you apply pressure equally on the left and proper sides of your physique, you develop into a extra environment friendly—and quicker—runner. Extra importantly, you’re much less vulnerable to harm.
Floor Contact Time (GCT) Stability is a metric that may assist enhance your working symmetry.
On this article, rise up to hurry on floor contact time stability and see our 5 suggestions for enhancing working symmetry.
What’s floor contact time?
To know floor contact time stability, let’s begin with floor contact time, or GCT for brief. That is the size of time your foot is involved with the bottom when working. For many runners, a GCT between 200 and 300 milliseconds is regular. Elite distance runners are able to sub-200ms floor contact occasions.
The bottom contact portion of your working gait is often known as the stance part. The stance part begins with the preliminary foot strike, continues via the ‘load bearing’ midstance, and ends with toe-off.
Why does floor contact time matter?
Working velocity depends on the power to use pressure via the bottom shortly. The quicker you possibly can apply pressure via the bottom, the faster you may be propelled ahead.
Scientists have studied the hyperlink between floor contact time and working velocity for many years. However till just lately, GCT was an inaccessible metric reserved for biomechanists in a laboratory.
Biofeedback and wearable expertise
Wearable health units have revolutionzed health coaching and the way we monitor our efficiency. Trackers and accelerometers now supply correct, real-time biofeedback for runners in all places.They usually work.
A 2020 research was the primary to assessment the results of wearable gadget biofeedback on working biomechanics. [1] The outcomes had been constructive. Seeing GCT biofeedback decreased runners’ vertical displacement (bouncing) and working time and elevated knee flexion–key components for efficiency and harm prevention.
That brings us to the following evolution in biofeedback: GCT stability.
What’s floor contact time stability?
Floor contact time stability is the measure of how comparable your left and proper leg floor contact occasions are. GCT stability is often displayed as a proportion cut up. A 50/50 cut up is the theoretical optimum and signifies an equal GCT for each legs. In actuality, GCT stability is never 50/50. Something between 49% and 51% is taken into account pretty symmetrical. Nonetheless, in case your GCT stability is past 49/51 (an imbalance of greater than 2%) the asymmetry could have an effect on your efficiency and put you liable to harm.
Floor contact time stability is the measure of how comparable your left and proper leg floor contact occasions are.
GCT stability is often displayed as a proportion cut up. A 50/50 cut up is the theoretical optimum and signifies an equal GCT for each legs.
In actuality, GCT stability is never 50/50. Something between 49% and 51% is taken into account pretty symmetrical. Nonetheless, in case your GCT stability is past 49/51 (an imbalance of greater than 2%) the asymmetry could have an effect on your efficiency and put you liable to harm.
Why does floor contact time stability matter?
Some health tracker options are little greater than gimmicks (e.g., oxygen saturation) [2][3]. So what makes GCT stability any completely different?
GCT stability issues as a result of symmetry issues. Elite athletes show excessive ranges of symmetry, and the quickest runners are essentially the most symmetrical. [4]
Asymmetry, alternatively, is metabolically and biomechanically inefficient. It’s because one aspect of your physique is working tougher to compensate for the opposite.
For environment friendly ahead movement, front-to-back (sagittal) motion is handiest. When an imbalance exists, power is wasted shifting your physique within the frontal airplane (assume hip adduction) or transverse airplane (assume trunk rotation) to counter the asymmetry.
For instance, if one leg is weaker or much less versatile, we are likely to compensate with extreme arm swing or trunk rotation.
What the science says about GCT stability
The Worldwide Journal of Train Science printed analysis final yr on the affect of GCT imbalance on working economic system. [5]
Remarkably, the research confirmed that for every 1% imbalance in GCT, working economic system was decreased by nearly 4%.
To place that in perspective, for a GCT stability of 49/51 (the place one leg is involved with the bottom simply 2% longer than the opposite), the power required to run on the identical velocity is 7.4% better.
For a 70kg runner at 15km/hr, this may enhance oxygen consumption by ~4ml.kg.min. That’s a giant chunk of your V̇O2 max.
The science is unclear in regards to the extent to which asymmetry causes harm. [6] Anecdotally, nonetheless, any weak point on one aspect is prone to put further pressure on different muscular tissues and joints, placing you liable to additional harm. [7]
In brief, balancing the time you spend on every foot issues for stopping harm and enhancing economic system and efficiency.
Listed below are 5 Ideas for enhancing working symmetry and floor contact time stability
1. Establish the asymmetry
Use the GCT stability metric to determine which leg is slower. The leg with the upper GCT stability proportion (>50) is spending extra time involved with the bottom. The slower leg is the one to work on.
Take a look at the asymmetry by performing a stretch or train on every leg. This may provide help to determine variations in power, stability and adaptability.
- How lengthy are you able to stand on every leg along with your eyes closed?
- Does your knee flip in on one aspect throughout a lunge?
- How far does every leg attain when mendacity in your again and stretching your hamstring?
2. Deal with previous accidents
In lots of instances, asymmetries stem from previous accidents. The ache or weak point of 1 injured physique half can result in overcompensation in others. Asymmetry turns into a vicious cycle of overcompensation, inflicting additional weak point on the injured aspect resulting from underuse.
Use GCT stability biofeedback to right asymmetry when recovering from harm, or to retrain after adaptation to previous accidents.
3. Strengthen muscle
To enhance working symmetry and overcome imbalances in floor contact time, deal with creating muscular power and energy.
Single leg (unilateral) workout routines like lunges and calf raises are efficient at creating your weaker leg and forestall the dominant leg from taking on.
4. Optimise flexibility and stiffness
Inflexibility resulting from harm (from scar tissue for instance) will increase the chance of asymmetry. Embrace flexibility coaching in your schedule to beat harm associated tightness.
Your vary of movement needs to be particular to your exercise. You don’t want a gymnast’s flexibility to run lengthy distances. Actually, a sure diploma of ‘tightness’ could even improve efficiency. [8]
A latest research confirmed that runners naturally adapt leg stiffness and floor contact time to optimise working economic system. [9] A stiffer leg spring will return extra power after compression.
Incorporate single leg plyometric workout routines into your programme to boost leg spring stiffness and shorten floor contact time.
5. Differ terrain
Working over monotonous terrain can exacerbate asymmetry. Attempt working over tough floor and quite a lot of gradients to boost proprioception, stability and power.
When you run on a monitor, alternate between clockwise and anticlockwise laps to keep away from asymmetry resulting from leaning into the curve. [10][4]
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